TPA6140A2 clicking when changing volume

Hi Paul,

I will work with you on this. Are you using the EVM, what is your setup?

Regards,

Matt

Thanks Matt.

I am not using the EVK, this is my (partial) schematic:

I am doing some low-pass filtering on the audio which comes in as the FILTERED signal.

I noticed your post title is the TPA6140A2 and the device in the schematic is the TPA6130A2.

Can you verify which part you are having the issue with?

-Matt

Sorry, the schematic is correct. I copy/pasted the other one in error.

Hi Paul,

Your schematic looks correct for this part so the noise is most likely from discontinuity during large jumps in volume.

This will be most apparent with a sin wave input and minimal to non-detectable with true audio sources. The best way to minimize this is to create incremental changes in volume rather than large jumps. You should notice that the clicking will be undetectable with small volume steps up to or down to the desired level rather than one large jump.

Regards,

Matt

I am only changing the volume by +/-2 each time and it still clicks. I tried changing it by 1 step at a time but there is still some background noise. Does the IC do zero crossing detection or anything like that?

I would recommend using tight tolerance caps of 5% or better on the differential inputs if they aren’t already. Capacitance imbalance can cause transient noise on the inputs.

Do you have a scope shot of the noise?

-Matt